uk.ac.starlink.ttools.plot2.paper

Class Compositor.BoostCompositor

java.lang.Object

uk.ac.starlink.ttools.plot2.paper.Compositor

uk.ac.starlink.ttools.plot2.paper.Compositor.BoostCompositor

Enclosing class:

Compositor

public static class Compositor.BoostCompositor
extends Compositor

Compositor with boosted saturation. This acts like Compositor.SATURATION except that any pixel with a non-zero alpha has its alpha value boosted to a given minimum. The effect is that even very slightly populated pixels can be visually distinguished from unpopulated pixels, which is not the case for standard saturation composition.

Nested Class Summary

Nested classes/interfaces inherited from class uk.ac.starlink.ttools.plot2.paper.Compositor

Compositor.BoostCompositor, Compositor.Buffer

Field Summary

Fields inherited from class uk.ac.starlink.ttools.plot2.paper.Compositor

SATURATION

Constructor Summary

Constructors

Constructor and Description
BoostCompositor(float boost) Constructor.

Method Summary

Modifier and Type	Method and Description
Compositor.Buffer	createBuffer(int count) Creates a buffer on which compositing operations can be performed.
float	getBoost() Returns the boost value for this compositor.
float	scaleAlpha(float alpha) Adjusts an alpha value in accordance with this compositor's policy.

Methods inherited from class uk.ac.starlink.ttools.plot2.paper.Compositor

byteToFloat, floatToByte, srcOverOpaque

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BoostCompositor

public BoostCompositor(float boost)

Constructor. The boost value must be in the range 0..1; zero is equivalent to Compositor.SATURATION.

Parameters:

boost - minimum alpha output for non-empty pixel

Method Detail

createBuffer

public Compositor.Buffer createBuffer(int count)

Description copied from class: Compositor

Creates a buffer on which compositing operations can be performed.

Specified by:

createBuffer in class Compositor

Parameters:

count - number of pixel elements in buffer

Returns:

new buffer

scaleAlpha

public float scaleAlpha(float alpha)

Description copied from class: Compositor

Adjusts an alpha value in accordance with this compositor's policy. It takes an alpha value in the range 0-1 and maps it into the range to be used for output from this compositor.

Specified by:

scaleAlpha in class Compositor

Parameters:

alpha - input alpha in range 0-1

Returns:

adjusted alpha, also in range 0-1

getBoost

public float getBoost()

Returns the boost value for this compositor.

Returns:

boost value in range 0..1